Approximately 13,000 BC- 12,000 BC: Mass migrations into the North American heartland are becoming possible now as the ice retreats

There is fighting and competition within the new migratory waves as well as between them and peoples already living on the continent from previous immigration.

Around 13,000 BC to 12,000 BC the continental glaciers have sufficiently retreated to offer more hospitable inland routes south through the continent than before. This allows perhaps larger mass migrations to proceed inland compared to the traveling possible along the coast, for both people and animals.

There appears to be frequent and intense conflict occurring among these early migratory peoples.